What is rate limiting?
Sequences are fantastic for automating outreach and communications to hundreds of contacts. However, if you try to send to too many people at once, you might hit Gmail's rate limits—meaning your account could be limited if you send a high volume of messages in a short period.
Since Mixmax sends your messages through your Gmail account, Mixmax is subject to any limitations set by Google, including rate limiting. Google monitors the rate at which messages are sent through your account, not just the total number of messages you send in a 24-hour period. To prevent this, we use a sophisticated algorithm that makes Google think you're sending the messages manually. If you upload a recipient list with more than 500 recipients, we'll space out the sending over multiple weekdays, sending to 500 recipients per day. We send the messages individually and space them out over time. If you want to send emails to more than 2,000 recipients, we recommend sending them in batches, a few days apart.
If you routinely send daily emails to more than 2,000 people at once — i.e., for marketing automation — we recommend using a marketing automation tool. Mixmax is currently optimized for sending individual, personalized messages at scale directly from Gmail — but not for sending thousands of emails each day.
Mixmax may limit the number of emails a single user can send in a day to 1000 to prevent rate limiting. You can learn more about Google-specific account limits.
Additional key factors related to rate limiting
Keep in mind that several factors affect the exact number of messages you can send. Below are a few factors that can affect your email reputation and how Google treats your account when sending emails in bulk.
If your bounce rate is high and/or you're sending emails to malformed or invalid email addresses, you are much more likely to be rate-limited.
If recipients are marking your emails as spam, you are much more likely to be rate-limited. Each time a recipient clicks Mark as spam in Gmail, Gmail penalizes the sender by reducing their daily send quota.
Prior sending behavior on your account will affect your limit. To learn more, see Optimizing email deliverability.
Sending rate matters as much as the number of messages sent per day. Google customers can send up to 2,000 emails per day, but cannot send them all at once. You must space sends out over time - Mixmax Sequences does this for you.
Also, make sure your email is configured so recipient email servers can route messages correctly. Google mentions in its bulk-sending guidelines that you should publish your SPF and DMARC records. Here's how you can check these settings in Mixmax.
Google's recommendations for sending bulk email
Google shares tips in its Help Center to help you get the best results from bulk sending. These are some of the ways (directly from Google) to avoid exceeding limits when sending a large amount of mail, such as for a marketing campaign:
Stagger mass communications over 2 days: Send messages to one group of recipients, wait 24 hours, and then send the rest to the other group.
Review bulk-sending guidelines and best practices: Some email recipients may report bulk messages as spam. Therefore, ensure all recipients are willing to receive the emails. You can also check email settings for any incorrectly configured forwarding rules or filters. For details, see Google's bulk sending guidelines and best practices.
How many sequence recipients can I send my sequences to?
This section covers batch size and upload limits. For the monthly limit on how many recipients you can enroll based on your plan, see Sequence recipients limit.
Mixmax has some safeguards in place to help prevent your account from getting rate-limited. You can upload a CSV (or import a list of recipients) with up to 2,000 recipients (please note that Salesforce DOES limit you to 200 recipients per import; we recommend breaking down your Salesforce lists accordingly). If you upload a recipient list with more than 500 recipients, we'll space out the sending over multiple weekdays, sending to 500 recipients per day. We send the messages individually and space them out over time. If you want to send emails to more than 2,000 recipients, we recommend sending them in batches, a few days apart. To schedule a later batch, choose At a custom start time when you activate the recipients.
Alternatively, you can send from multiple Gmail accounts—just share your sequence with someone on your team.
How will I know if I get rate-limited?
Rate limiting can be frustrating and, in some cases, can halt your work. If your account is rate-limited, you will receive a notification from Google by email. Depending on the rate-limiting event, it can last from a few minutes to 24 hours (or longer in sporadic cases).
Typically, when rate-limiting events occur, Google will prevent all emails from leaving your account. This includes individual messages you try to send outside any Mixmax sequences or other campaigns you have running. Keep in mind that rate-limiting events will prevent all connected services from accessing your email, not only Mixmax.
What happens to my sequences when I get rate-limited?
In a rate-limiting event, Mixmax will keep trying to send to active sequence recipients for up to 12 hours from the initial delivery time. In many cases, that is enough time for the rate limit to be lifted, and your emails will be sent a little later than initially scheduled.
If your account is limited for more than 12 hours, Mixmax will mark the recipients as failed and email you to let you know we couldn't send the sequence messages. In this case, you will need to resend the messages.
To keep upcoming stages from sending while your account is limited, you can pause the recipients in your active sequences and resume them when you're ready to send again. You can also reschedule individual emails from your Outbox.
How can I resend my sequences after getting rate-limited?
After your account is rate-limited, we recommend waiting 24 hours before retrying unsent messages to avoid triggering another rate limit. To retry messages, go to the Reports tab for the affected sequence. The email you received from Mixmax includes a link to the specific sequence.
In the Reports tab, you should see a red button with an error message indicating that some messages couldn't be sent. Click the Resend to x recipients button — see screenshot below:
When you click the button, your emails will start retrying immediately. The send times will be spaced out to minimize the chance of being rate-limited again.